• Title/Summary/Keyword: Expression and secretion

Search Result 922, Processing Time 0.035 seconds

Histamine Releasing Factor (HRF) Evokes [3H] Dopamine Release by a Ca^{2+} - independent Pathway in Pheochromocytoma Cells

  • Seo, Ji-Hui;Kim, Hwa-Jung
    • Proceedings of the PSK Conference
    • /
    • 2002.10a
    • /
    • pp.268.2-269
    • /
    • 2002
  • The recombinant histamine-releasing factor (rHRF) has been reported to induce a secretion of histamine and cytokines from inflammation-related cell types such as basophils and eosinophils. and to function as a growth factor in immune B cells. Recently. decreased expression level of HRF protein was observed in brain of patients with Alzheimer disease and Downs syndrome. suggesting a possible significant role in neurological systems. (omitted)

  • PDF

Regulation of Proopiomelanocortin and Melanocortin 1 Receptor by UVB: Inhibitory Effect of Antioxidants

  • Funasaka, Yoko
    • Journal of Photoscience
    • /
    • v.9 no.2
    • /
    • pp.201-204
    • /
    • 2002
  • Epidermal cells produce a panel of antioxidants as well as cytokines after UVB irradiation, which counteract reactive oxygen species, however, how these antioxidants might regulate melanogenesis is unclear. An important constituent of the cellular antioxidant buffering system which controls the redox state of proteins is thioredoxin (TRX), a 13-kD protein that catalyzes thiol-disulfide exchange reactions, regulates activation of transcription factors, and possesses several other biological functions similar to cytokines. TRX suppressed the UVB-induced production and secretion of $\alpha$-melanocyte stimulating hormone ($\alpha$-MSH) and of adrenocorticotropic hormone (ACTH), and also suppressed proopiomelanocortin (POMC) mRNA expression by normal human keratinocyte (KC)s. Further, L-cysteine, N-acetyl-cysteine, $\alpha$-tocopheryl ferulate showed suppressive effect on UVB-induced POMC mRNA expression. However, TRX released from UVB-irradiated KCs stimulated melanogenesis by up-regulating MSH receptor expression and its binding activity in melanocyte (MC)s. UVB-induced KC derived cytokines such as IL1, IL6, and ET1 upregulated MSH-receptor binding ability as well as MCl-R mRNA expression in cultured normal human MCs. MCl-R has a tendency to be upregulated by UVB-induced KC-derived cytokines as well as by direct UVB irradiation. These results suggest that antioxidants such as TRX suppresses UVB induction of POMC, but in the case of MCl-R, this gene can be mainly in the trend of upregulation by UVB-induced KC-derived factors including TRX.

  • PDF

Effective Platform for the Production of Recombinant Outer Membrane Vesicles in Gram-Negative Bacteria

  • Kunjantarachot, Anthicha;Phanaksri, Teva
    • Journal of Microbiology and Biotechnology
    • /
    • v.32 no.5
    • /
    • pp.621-629
    • /
    • 2022
  • Bacterial outer membrane vesicles (OMVs) typically contain multiple immunogenic molecules that include antigenic proteins, making them good candidates for vaccine development. In animal models, vaccination with OMVs has been shown to confer protective immune responses against many bacterial diseases. It is possible to genetically introduce heterologous protein antigens to the bacterial host that can then be produced and relocated to reside within the OMVs by means of the host secretion mechanisms. Accordingly, in this study we sought to develop a novel platform for recombinant OMV (rOMV) production in the widely used bacterial expression host species, Escherichia coli. Three different lipoprotein signal peptides including their Lol signals and tether sequences-from Neisseria meningitidis fHbp, Leptospira interrogans LipL32, and Campylobactor jejuni JlpA-were combined upstream to the GFPmut2 model protein, resulting in three recombinant plasmids. Pilot expression studies showed that the fusion between fHbp and GFPmut2 was the only promising construct; therefore, we used this construct for large-scale expression. After inducing recombinant protein expression, the nanovesicles were harvested from cell-free culture media by ultrafiltration and ultracentrifugation. Transmission electron microscopy demonstrated that the obtained rOMVs were closed, circular single-membrane particles, 20-200 nm in size. Western blotting confirmed the presence of GFPmut2 in the isolated vesicles. Collectively, although this is a non-optimized, proof-of-concept study, it demonstrates the feasibility of this platform in directing target proteins into the vesicles for OMV-based vaccine development.

Expression of the EPO-like Domains of Human Thrombopoietin in Escherichia coli

  • Koh, Yeo-Wook;Koo, Tai-Young;Ju, Sang-Myoung;Kwon, Chang-Hyuk;Chung, Joo-Young;Park, Myung-Hwan;Yang, Jai-Myung;Park, Seung-Kook
    • Journal of Microbiology and Biotechnology
    • /
    • v.8 no.6
    • /
    • pp.553-559
    • /
    • 1998
  • cDNA of human thrombopoietin (hTPO) amplified by polymerase chain reaction from a cDNA library of human fetal liver was cloned. EPO-like domains ($hTPO_{153} \;or\; hTPO_{l63})\; of\; hTPO(hTPO_{332}$) were expressed in Escherichin coli using several kinds of expression systems, such as ompA secretion, thioredoxin fusion, and the $P_L$ and T7 expression systems. To obtain $hTPO_{153}$ in soluble form, $hTPO_{153}$ cDNA was fused in-frame behind the gene encoding ompA signal sequence and thioredoxin protein. When fused with either of the genes, $hTPO_{153}$ was not expressed to the detectable level. However, a high level expression of the EPO-like domain of hTPO was obtained using the PL and T7 expression system. $hTPO_{153} \;or\; hTPO_{l63} cDNA were subcloned into the pLex and pET-28a(+) vectors under the control of the inducible$ P_L\;T_7$ promoter, respectively. Proteins expressed using pl.ex vector and pET-28a(+) detected in insoluble forms with an expression level of about 14% and 9% of total cellular proteins, respectively, and the level of expression was rapidly diminished in 2 h after the maximum level of expression was reached.

  • PDF

Tumor necrosis factor-α converting enzyme (TACE) increases RANKL expression in osteoblasts and serves as a potential biomarker of periodontitis

  • Lee, Ji-Hyun;Choi, Young-Jin;Heo, Sun-Hee;Lee, Jae-Mok;Cho, Je-Yoel
    • BMB Reports
    • /
    • v.44 no.7
    • /
    • pp.473-477
    • /
    • 2011
  • Periodontitis is a very prevalent disease. Therefore, biomarkers for the early and standard diagnoses of periodontitis are urgently needed. TACE is a membrane-bound metalloprotease. Although a recent study suggested that TACE levels in GCF are elevated during periodontal disease, the levels of TACE in GCF at different stages of chronic periodontitis have not been determined. Here, we analyzed the protein levels of TACE in GCF from periodontal disease subjects and confirmed that the protein levels of TACE were higher in the moderate periodontitis groups. TACE is known to be a NF-${\kappa}B$ ligand that stimulates RANKL secretion in osteoblasts. To understand the effects of TACE on RANKL and OPG in osteoblasts, we treated MG63 cells with TACE. We observed an increase in RANKL protein expression but a decrease in OPG protein expression. Our data suggest that TACE can induce RANKL expression and promote osteoclastogenesis, thus worsening the outcome of periodontitis.

형질전환 식물세포배양을 이용한 monoclonal antibody(mAb)의 생산

  • Hong, Sin-Yeong;Gwon, Tae-Ho;Jang, Yong-Seok;Yang, Mun-Seok
    • 한국생물공학회:학술대회논문집
    • /
    • 2001.11a
    • /
    • pp.215-216
    • /
    • 2001
  • Mouse monoclonal antibody(mAb) with an antigen specificity for major histocompatibility complex class Il(MHC class II) was produced and secreted from tobacco cell suspension culture by successive sexual crossesu. Expression and secretion of assembled antibody was observed in transgenic tobacco cell suspension culture by wetern blot analysis.

  • PDF

Anti-stress effects of ginseng via down-regulation of tyrosine hydroxylase (TH) and dopamine ${\beta}$-hydroxylase (DBH) gene expression in immobilization-stressed rats and PC12 cells

  • Kim, Yang-Ha;Choi, Eun-Ha;Doo, Mi-Ae;Kim, Joo-Yeon;Kim, Chul-Jin;Kim, Chong-Tai;Kim, In-Hwan
    • Nutrition Research and Practice
    • /
    • v.4 no.4
    • /
    • pp.270-275
    • /
    • 2010
  • Catecholamines are among the first molecules that displayed a kind of response to prolonged or repeated stress. It is well established that long-term stress leads to the induction of catecholamine biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine ${\beta}$-hydroxylase (DBH) in adrenal medulla. The aim of the present study was to evaluate the effects of ginseng on TH and DBH mRNA expression. Repeated (2 h daily, 14 days) immobilization stress resulted in a significant increase of TH and DBH mRNA levels in rat adrenal medulla. However, ginseng treatment reversed the stress-induced increase of TH and DBH mRNA expression in the immobilization-stressed rats. Nicotine as a ligand of the nicotinic acetylcholine receptor (nAChR) in adrenal medulla stimulates catecholamine secretion and activates TH and DBH gene expression. Nicotine treatment increased mRNA levels of TH and DBH by 3.3- and 3.1-fold in PC12 cells. The ginseng total saponin exhibited a significant reversal in the nicotine-induced increase of TH and DBH mRNA expression, decreasing the mRNA levels of TH and DBH by 57.2% and 48.9%, respectively in PC12 cells. In conclusion, immobilization stress induced catecholamine biosynthetic enzymes gene expression, while ginseng appeared to restore homeostasis via suppression of TH and DBH gene expression. In part, the regulatory activity in the TH and DBH gene expression of ginseng may account for the anti-stress action produced by ginseng.

Zinc upregulates bone-specific transcription factor Runx2 expression via BMP-2 signaling and Smad-1 phosphorylation in osteoblasts

  • Cho, Young-Eun;Kwun, In-Sook
    • Journal of Nutrition and Health
    • /
    • v.51 no.1
    • /
    • pp.23-30
    • /
    • 2018
  • Purpose: Runx2 (runt-related transcription factor 2), a bone-specific transcription factor, is a key regulator of osteoblast differentiation and its expression is induced by the activation of BMP-2 signaling. This study examined whether zinc modulates BMP-2 signaling and therefore stimulates Runx2 and osteoblast differentiation gene expression. Methods: Two osteoblastic MC3T3-E1 cell lines (subclones 4 as a high osteoblast differentiation and subclone 24 as a low osteoblastic differentiation) were cultured in an osteogenic medium (OSM) as the normal control, Zn-($1{\mu}M$ Zn) or Zn+($15{\mu}M$ Zn) for 24 h. The genes and proteins for BMP-2 signaling (BMP-2, Smad-1/p-Smad-1), transcription factors (Runx2, osterix), and osteoblast differentiation marker proteins were assessed. Results: In both cell lines, BMP-2 mRAN and protein expression and extracellular BMP-2 secretion all decreased in Zn-. The expression of Smad-1 (downstream regulator of BMP-2 signaling) and p-Smad-1 (phosphorylated Smad-1) also downregulated in Zn-. Furthermore, the expression of the bone-specific transcription factors, Runx2 and osterix, decreased in Zn-, which might be due to the decreased BMP-2 expression and Smad-1 activation (p-Smad-1) by Zn-, because Runx2 and osterix both are downstream in BMP-2 signaling. Bone marker gene expression, such as alkaline phosphatase (ALP), collagen type I (COLI), osteocalcin, and osteopontin were also downregulated in Zn-. Conclusion: The results suggest that a zinc deficiency in osteoblasts suppresses the BMP-2 signaling pathway via the suppression of Smad-1 activation, and this suppressed BMP-2 signaling can cause poor osteoblast differentiation.

Effect of Chitosan on Nitric Oxide Content and Inducible Nitric Oxide Synthase Activity in Serum and Expression of Inducible Nitric Oxide Synthase mRNA in Small Intestine of Broiler Chickens

  • Li, H.Y.;Yan, S.M.;Shi, B.L.;Guo, X.Y.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.22 no.7
    • /
    • pp.1048-1053
    • /
    • 2009
  • The present study was conducted to determine the effects of chitosan on nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in serum, and relative expression of iNOS mRNA in the duodenum, jejunum, and ileum of broiler chickens. A total of 240 one-day-old Arbor Acre mixed-sex broiler chickens were randomly allotted to six dietary treatments with five replicates in each treatment and eight chickens in each replicate. The broiler chickens in the six treatments were fed the basal diet supplemented with 0 (control), 0.05, 0.2, 0.5, 1.0 or 2.0 g/kg chitosan. The trial lasted for 42 days. The results showed that dietary chitosan enhanced NO content and iNOS activity in serum as well as iNOS mRNA expression in the duodenum and ileum of broiler chickens in a quadratic dose-dependent manner (p<0.05), and improved jejunum iNOS mRNA expression in a quadratic dose-dependent manner (p<0.10) with increasing addition of chitosan. Chicks fed a diet containing 0.5-1.0 g/kg chitosan had higher NO content and iNOS activity in serum as well as small-intestinal iNOS mRNA expression compared with birds given the control diet, but positive effects of chitosan tended to be suppressed when addition of chitosan in the diet was increased to 2.0 g/kg. These results implied that there was a threshold level of chitosan inclusion beyond which progressive reductions in serum NO content and small intestinal iNOS expression occured, and the regulation of chitosan on immune functions in chickens is probably associated with activated expression of iNOS and NO secretion.

Expression System for Optimal Production of Xylitol Dehydrogenase (XYL2) in Saccharomyces cerevisiae (출아효모에서 xylitol dehydrogenase (XYL2)의 최적 생산을 위한 발현 시스템 구축)

  • Jung, Hoe-Myung;Kim, Yeon-Hee
    • Journal of Life Science
    • /
    • v.27 no.12
    • /
    • pp.1403-1409
    • /
    • 2017
  • In this study, the xylitol dehydrogenase (XYL2) gene was expressed in Saccharomyces cerevisiae as a host cell for ease of use in the degradation of lignocellulosic biomass (xylose). To select suitable expression systems for the S.XYL2 gene from S. cerevisiae and the P.XYL2 gene from Pichia stipitis, $pGMF{\alpha}-S.XYL2$, $pGMF{\alpha}-P.XYL2$, $pAMF{\alpha}-S.XYL2$ and $pAMF{\alpha}-P.XYL2$ plasmids with the GAL10 promoter and ADH1 promoter, respectively, were constructed. The mating factor ${\alpha}$ ($MF{\alpha}$) signal sequence was also connected to each promoter to allow secretion. Each plasmid was transformed into S. cerevisiae $SEY2102{\Delta}trp1$ strain and the xylitol dehydrogenase activity was investigated. The GAL10 promoter proved more suitable than the ADH1 promoter for expression of the XYL2 gene, and the xylitol dehydrogenase activity from P. stipitis was twice that from S. cerevisiae. The xylitol dehydrogenase showed $NAD^+$-dependent activity and about 77% of the recombinant xylitol dehydrogenase was secreted into the periplasmic space of the $SEY2102{\Delta}trp1/pGMF{\alpha}-P.XYL2$ strain. The xylitol dehydrogenase activity was increased by up to 41% when a glucose/xylose mixture was supplied as a carbon source, rather than glucose alone. The expression system and culture conditions optimized in this study resulted in large amounts of xylitol dehydrogenase using S. cerevisiae as the host strain, indicating the potential of this expression system for use in bioethanol production and industrial applications.